On 2025-11-17 10:00, Philip Yang wrote:
On 2025-11-14 18:26, Felix Kuehling wrote:
On 2025-11-13 16:09, Xiaogang.Chen wrote:
From: Xiaogang Chen <[email protected]>
Fixes: 7ef6b2d4b7e5 (drm/amdkfd: remap unaligned svm ranges that
have split)
When split svm ranges that have been mapped using huge page should
use huge
page size(2MB) to check split range alignment, not
prange->granularity that
means migration granularity.
Signed-off-by: Xiaogang Chen <[email protected]>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 521c14c7a789..c60d8134db45 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1146,11 +1146,14 @@ svm_range_split_tail(struct svm_range
*prange, uint64_t new_last,
{
struct svm_range *tail = NULL;
int r = svm_range_split(prange, prange->start, new_last, &tail);
+ bool huge_page_mapping = IS_ALIGNED(prange->start, 512);
Instead of hard-coding 512 here, it would be more future-proof to
call amdgpu_vm_pt_num_entries(adev, AMDGPU_VM_PDB0). That's currently
a static function in amdgpu_vm_pt.c. Christian, would you object to
making that non-static?
We don't have method to know if prange has huge page mapping which
depends on virtual address 2MB align and physical address contiguous,
it is decided inside amdgpu_vm_ptes_update. Even prange->start is not
2MB align, prange could have huge page mapping.
Right, I guess the correct condition would check that the range contains
at least one potential huge page. I.e., the start address aligned up to
2MB is larger and the end address aligned down to 2MB. And the unaligned
split is between those two aligned addresses.
Regards,
Felix
Regards,
Philip
Also, to improve the check whether the range can really use huge
pages, you could add a check that it's size is at least 512 pages.
if (!r) {
list_add(&tail->list, insert_list);
- if (!IS_ALIGNED(new_last + 1, 1UL << prange->granularity))
- list_add(&tail->update_list, remap_list);
+ if (huge_page_mapping) {
+ if (!IS_ALIGNED(tail->start, 512))
Make that one condition: if (huge_page_mapping && !IS_ALIGNED...)
+ list_add(&tail->update_list, remap_list);
+ }
}
return r;
}
@@ -1162,11 +1165,16 @@ svm_range_split_head(struct svm_range
*prange, uint64_t new_start,
struct svm_range *head = NULL;
int r = svm_range_split(prange, new_start, prange->last, &head);
+ bool huge_page_mapping = IS_ALIGNED(prange->start, 512);
Why the blank line before huge_page_mapping? It's part of your
variable declarations.
+
if (!r) {
list_add(&head->list, insert_list);
- if (!IS_ALIGNED(new_start, 1UL << prange->granularity))
- list_add(&head->update_list, remap_list);
+ if (huge_page_mapping) {
+ if (!IS_ALIGNED(prange->start, 512))
Same as above.
Regards,
Felix
+ list_add(&head->update_list, remap_list);
+ }
}
+
return r;
}
